There has been a demand for improvement in wet resistance and uneven wear resistance of heavy duty pneumatic tires. To satisfy the demand, approaches for improving the above performance have been made in recent years by forming various types of sipes on ribs.
As a conventional pneumatic tire employing the above configuration, a technology disclosed in Patent Document 1 is known. The conventional pneumatic tire (pneumatic tire for vehicles for driving on the left) has a plurality of ribs on a tread. The ribs are sectioned by a plurality of circumferential direction main grooves extending in the circumferential direction of the tire. On at least one of the ribs, a plurality of sipes extending across the rib is formed. All the sipes extend right upwardly and are oblique to the tire axial direction.
Patent Document 1: Japanese Patent Application Laid-open No. 2002-103922